Testosterone is a steroid hormone secreted by interstitial or Leydig cells of the normal testis. The determination of testosterone concentrations in the body fluids is of great value for endocrinological investigations. Useful in identification of testicular tumors arising from interstitial cells. Applications: Suitable for use in ELISA. Other applications not tested. Recommended Dilution: Optimal dilutions to be determined by the researcher. Storage and Stability: May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.